Throughout the world, it is a common and growing practice to utilize conventional plastic molded cups and containers to display promotional messages and to increase the market value of the cups and containers by adding images of sports figures, movie and television personalities, and other graphics. While the printing processes for producing these messages, images, and graphics have improved in recent years with advances in printing technologies, the messages, characters, and other graphics have generally remained two dimensional, static and non-moveable. The expectations of purchasers of these containers continues to rise, and the general public continues to demand ever increasing and enhanced visual effects in all media. Specifically, the entertainment industry routinely licenses its proprietary images for use on cups, packaging, and containers of all types from plastic soda cups to popcorn containers and their lids.
The entertainment industry uses bright colors and molded shapes extensively to excite and interest consumers and collectors of these containers. There continues to be pressure from movie makers, sports promoters and others in the entertainment industry to develop new products to better capture the public's attention for their promotions and licensed products.
In addition to problems with creating more exciting imagery, there are design restraints faced by plastic cup and container manufacturers that must be addressed in creating any new product. For example, in the traditional plastic cup industry, the manufacturers are continuously struggling with the demands for a less expensive cup to make their use attractive as part of no-cost promotional campaigns (e.g., the cup is given away by a retailer with the purchase of soda, beer, or other beverage) and as a profitable standalone product. One method used to reduce cost is to reduce the amount or weight of plastic used in each cup by thinning the cup wall and other methods. Reducing the weight of plastic used reduces material costs and also makes the manufacturing (i.e., molding) of the cups faster and less expensive as the molds can be filled more rapidly and the plastic cools in a shorter time. However, the desired for less material weight and wall thickness must be balanced with the need for a cup with sufficient hoop strength. Hoop strength is a measure of the resistance of a cup to being squeezed shut or deformed. It is typically measured by adding weights or pressure to a point near the top of the cup on the outer surface of the side wall and measuring the amount of deflection of the open end of the cup.
To further minimize the costs of containers, the inner and outer surfaces of the walls are typically kept smooth and their shape kept relatively simple to minimize mold costs. These smooth surfaces also have been required because the typical method of plastic images and graphics on containers and other plastic objects is with standard printing processes, such as offset printing, that are most effective on smooth printing surfaces.
The inventors and others in the plastic cup and container manufacturing industry recognize the needs of the entertainment industry and understand the benefits of providing more visually appealing images and graphics as part of promotional cup or container and other plastic products. In this regard, the inventors and others in the industry believe that these plastic products will be significantly improved by including a three dimensional (“3D”), action image provided with the use of lenticular lens material or sheets (i.e., interlaced segments of images combined with lenticular lenses to provide a variety of visual effects such as motion, zooming in and out, and 3D effects). For example, a cup with Mark McGuire's 70th home run or a favorite scene from a recent Star Wars movie provided in dramatic 3D in a durable, reusable container is appealing and interesting to consumers and seen as a break through to the entertainment industry.
The use of lenticular lens material is known in the printing industry for use in creating promotional material and typically involves producing a sheet of lenticular lens material and adhesively attaching the lenticular lens material to a separately produced object for display. The production of lenticular lenses is well-known and described in detail in a number of U.S. patents, including U.S. Pat. No. 5,967,032 to Bravenec et al. In general, the production process includes selecting segments from visual images to create a desired visual effect and interlacing the segments (i.e., planning the layout of the numerous images), lenticular lenses are then mapped to the interlaced or planned segments, and the lenticular lenses are fabricated according to this mapping. The lenticular lenses generally include a transparent web which has a flat side or layer and a side with optical ridges and grooves formed by lenticules (i.e., convex lenses) arranged side-by-side with the lenticules or optical ridges extending parallel to each other the length of the transparent web. To provide the unique visual effects, ink is applied or printed directly to the flat side of the transparent web to form the interlaced segments and forming a thin, generally opaque ink layer in the produced lenticular lens material or sheet.
While these lenticular lens materials provide excellent visual effects, the use of adhesives and other attachment methods has not proven effective in producing a quality, long-lasting, and inexpensive plastic products. Because attaching the lenticular lens material after producing the plastic cup or container is inefficient and relatively expensive, the plastic manufacturing industry desires a method for attaching the lenticular lens material to a plastic cup or container as part of the cup or container manufacturing process. Unfortunately, the plastic manufacturing industry has not been able to overcome the problems associated with using common lenticular lens material as part of standard plastic fabrication processes. The problems arise because plastic fabrication generally includes processes such as injection molding that involve heating raw plastic materials to a relatively high temperature (e.g., 400° to 500° F. or hotter) and then injecting the fluid plastic into a mold with the shape of the desired plastic object or by otherwise processing the molten plastic. While the transparent web of the lenticular material may not be damaged by these high temperatures, the ink or ink layer has a chemistry that will not stay intact when the ink is heated to these high temperatures, and the image will be destroyed or at least significantly altered. Additionally, even if the ink could withstand the heat of plastic fabrication processes, the plastic manufacturing industry has not been able to engineer an inexpensive and efficient attachment process that effectively bonds the ink layer, and therefore, the lenticular lens material, to the plastic of the formed product.
Consequently, there remains a need for a method of fabricating plastic containers and other objects that includes lenticular lens material, and preferably, a fabrication method that overcomes the problem of bonding the lenticular lens material to plastic in a cost effective and structurally acceptable manner. Additionally, there remains needs for plastic objects with improved physical characteristics that can be manufactured inexpensively, such as a plastic cup with improved hoop strength and less plastic weight.